Peter Mandelson is being grilled on Monday by MEPs before he can become the European Union's new trade commissioner. BBC News Online explains what the job involves.

What are European commissioners?

From 1 November there will be 25 European commissioners, one nominated by each of the member states. Each takes charge of one policy area, they are appointed for five years and are expected to act in the general European interest rather than in their own country's interest. They are assisted by 25,000 civil servants who make up the rest of the European Commission. A commissioner gets paid £145,590.

What do they do?

The main job is to propose new policies for the EU and to make sure policies given the go ahead by the European Parliament and Council of Ministers are implemented properly and money spent properly.

How powerful could Mr Mandelson be?

BBC Europe correspondent Tim Franks says the new role would make Mr Mandelson more powerful than many British Cabinet ministers. He will be the embodiment of the EU as a global trading superpower - something the union cannot claim to be in the diplomatic or military spheres. Ministers from EU member states decide what the union's stance on trade should be, but the commissioner has a major say in how that policy develops and is charged with putting it into practice.

What would his main responsibilities be?

He would negotiate multi-billion dollar trade deals on behalf of the whole European Union - either through the World Trade Organisation, or with the trading partners of EU countries.

He would also analyse where the EU's trade interests lie and help devise policies to attract investment on issues such as European competitiveness and farming policy.

Are there any especially topical issues coming up?

Yes, negotiating on behalf of the EU at the current round of world trade talks - the so-called Doha round - would be one of Mr Mandelson's major tasks in his new role.

A deal struck in August agreed a framework on opening up global trade - with the US and EU expected to reduce agricultural subsidies, while developing nations could cut tariffs on manufactured goods.

Mr Mandelson would have to continue the Doha talks, which could be concluded as early as the end of 2005.

Green campaigners are also urging him to oppose US appeals for the EU to accept genetically-modified foods. The commission says its strong rules on the sales of GM crops should be safe against any challenge.

And what about trade disputes?

Acting as advocate for the EU over issues which go to the World Trade Organisation's disputes panels would also be high on Mr Mandelson's agenda.

Outgoing trade commissioner Pascal Lamy took up the fight for the EU when the US imposed tariffs on steel imports from around the world, for example.

In August the WTO gave the EU and others the go-ahead to retaliate and impose their own sanctions.

The United States is reviewing its steel tariffs, but if it fails to act, it could be left to Mr Mandelson to decide whether to impose sanctions.

Does the role cover trading within the single market?

No, that would be handled by the incoming commissioner for internal market and services, Ireland's Charlie McCreevy.